Yup. Two quick ones in a row... I guess I'll have to start making them harder

Iodide is a great nucleophile and a great leaving group. Initial formation of the optically pure iodide is soon attacked by the good nucleophile I- to liberate the good leaving group I- to give the iodide with the opposite configuration. Repeated attack of I- to liberate I- eventually provides the racemate. No SN1 mechanism is proposed.